How to make MySQL table primary key auto increment?

To make MySQL table primary key auto increment, use the below syntax

CREATE TABLE yourTableName
   (
   yourColumnName INT(6) ZEROFILL NOT NULL AUTO_INCREMENT,
   PRIMARY KEY(yourColumnName)
   );

Let us first create a table and set primary key auto increment −

mysql> CREATE TABLE DemoTable
   (
   UserId INT(6) ZEROFILL NOT NULL AUTO_INCREMENT,
   PRIMARY KEY(UserId)
   );
Query OK, 0 rows affected (0.81 sec)

Insert some records in the table using insert command −

mysql> INSERT INTO DemoTable values();
Query OK, 1 row affected (0.12 sec)

mysql> INSERT INTO DemoTable values();
Query OK, 1 row affected (0.13 sec)

mysql> INSERT INTO DemoTable values();
Query OK, 1 row affected (0.10 sec)

mysql> INSERT INTO DemoTable values();
Query OK, 1 row affected (0.44 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+--------+
| UserId |
+--------+
| 000001 |
| 000002 |
| 000003 |
| 000004 |
+--------+
4 rows in set (0.00 sec)